The Geneva Reduction and Analysis Pipeline for High-contrast Imaging of planetary Companions

TL;DR

The paper introduces GRAPHIC, a Fourier transform-based ADI reduction pipeline for high-contrast imaging that improves data processing efficiency and detection limits compared to traditional methods.

Contribution

It presents a novel Fourier transform-based pipeline for high-contrast imaging data reduction, enhancing performance and detection capabilities.

Findings

Significant performance gains over conventional interpolation methods.

Improved point spread function and speckle subtraction.

Detection limits comparable to top existing pipelines.

Abstract

We present GRAPHIC, a new angular differential imaging (ADI) reduction pipeline where all geometric image operations are based on Fourier transforms. To achieve this goal the entire pipeline is parallelised making it possible to reduce large amounts of observation data without the need to bin the data. The specific rotation and shift algorithms based on Fourier transforms are described and performance comparison with conventional interpolation algorithm are given. Tests using fake companions injected in real science frames demonstrate the significant gain obtained by using geometric operations based on Fourier transforms compared to conventional interpolation. This also translates in a better point spread function and speckle subtraction with respect to conventional reduction pipelines, achieving detection limits comparable to current best performing pipelines. Flux conservation of the companions is also demonstrated. This pipeline is currently able to reduce science data produced by VLT/NACO, Gemini/NICI, VLT/SPHERE, and Subaru/SCExAO.